ALSA: firewire-lib: Add support for AMDTP in-stream and PCM capture

For capturing PCM, this commit adds the functionality to handle in-stream.
This is also applied for dual-wire mode.

Currently, capturing 32bit samples are supported.

When the sequence of in-packet has discontinuity of dbc, in-stream isn't handled
and amdtp_streaming_error() returns true.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp.c

@@ -39,6 +39,7 @@
  * only "Clock-based rate control mode" is supported
  */
 #define AMDTP_FDF_AM824		(0 << (CIP_FDF_SFC_SHIFT + 3))
+#define AMDTP_FDF_NO_DATA	0xff
 #define AMDTP_DBS_MASK		0x00ff0000
 #define AMDTP_DBS_SHIFT		16
 #define AMDTP_DBC_MASK		0x000000ff
@@ -47,6 +48,7 @@
 #define INTERRUPT_INTERVAL	16
 #define QUEUE_LENGTH		48
 
+#define IN_PACKET_HEADER_SIZE	4
 #define OUT_PACKET_HEADER_SIZE	0
 
 static void pcm_period_tasklet(unsigned long data);
@@ -179,6 +181,12 @@ static void amdtp_write_s16_dualwire(struct amdtp_stream *s,
 static void amdtp_write_s32_dualwire(struct amdtp_stream *s,
 				     struct snd_pcm_substream *pcm,
 				     __be32 *buffer, unsigned int frames);
+static void amdtp_read_s32(struct amdtp_stream *s,
+			   struct snd_pcm_substream *pcm,
+			   __be32 *buffer, unsigned int frames);
+static void amdtp_read_s32_dualwire(struct amdtp_stream *s,
+				    struct snd_pcm_substream *pcm,
+				    __be32 *buffer, unsigned int frames);
 
 /**
  * amdtp_stream_set_pcm_format - set the PCM format
@@ -200,16 +208,27 @@ void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
 		WARN_ON(1);
 		/* fall through */
 	case SNDRV_PCM_FORMAT_S16:
+		if (s->direction == AMDTP_OUT_STREAM) {
 			if (s->dual_wire)
 				s->transfer_samples = amdtp_write_s16_dualwire;
 			else
 				s->transfer_samples = amdtp_write_s16;
 			break;
+		}
+		WARN_ON(1);
+		/* fall through */
 	case SNDRV_PCM_FORMAT_S32:
+		if (s->direction == AMDTP_OUT_STREAM) {
 			if (s->dual_wire)
 				s->transfer_samples = amdtp_write_s32_dualwire;
 			else
 				s->transfer_samples = amdtp_write_s32;
+		} else {
+			if (s->dual_wire)
+				s->transfer_samples = amdtp_read_s32_dualwire;
+			else
+				s->transfer_samples = amdtp_read_s32;
+		}
 		break;
 	}
 }
@@ -420,6 +439,59 @@ static void amdtp_write_s16_dualwire(struct amdtp_stream *s,
 	}
 }
 
+static void amdtp_read_s32(struct amdtp_stream *s,
+			   struct snd_pcm_substream *pcm,
+			   __be32 *buffer, unsigned int frames)
+{
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, remaining_frames, i, c;
+	u32 *dst;
+
+	channels = s->pcm_channels;
+	dst  = (void *)runtime->dma_area +
+			frames_to_bytes(runtime, s->pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			*dst = be32_to_cpu(buffer[c]) << 8;
+			dst++;
+		}
+		buffer += s->data_block_quadlets;
+		if (--remaining_frames == 0)
+			dst = (void *)runtime->dma_area;
+	}
+}
+
+static void amdtp_read_s32_dualwire(struct amdtp_stream *s,
+				    struct snd_pcm_substream *pcm,
+				    __be32 *buffer, unsigned int frames)
+{
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, remaining_frames, i, c;
+	u32 *dst;
+
+	dst = (void *)runtime->dma_area +
+			frames_to_bytes(runtime, s->pcm_buffer_pointer);
+	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
+	channels = s->pcm_channels / 2;
+
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			*dst = be32_to_cpu(buffer[c * 2]) << 8;
+			dst++;
+		}
+		buffer += 1;
+		for (c = 0; c < channels; ++c) {
+			*dst = be32_to_cpu(buffer[c * 2]) << 8;
+			dst++;
+		}
+		buffer += s->data_block_quadlets - 1;
+		if (--remaining_frames == 0)
+			dst = (void *)runtime->dma_area;
+	}
+}
+
 static void amdtp_fill_pcm_silence(struct amdtp_stream *s,
 				   __be32 *buffer, unsigned int frames)
 {
@@ -504,6 +576,12 @@ static inline int queue_out_packet(struct amdtp_stream *s,
 			    payload_length, skip);
 }
 
+static inline int queue_in_packet(struct amdtp_stream *s)
+{
+	return queue_packet(s, IN_PACKET_HEADER_SIZE,
+			    amdtp_stream_get_max_payload(s), false);
+}
+
 static void handle_out_packet(struct amdtp_stream *s, unsigned int cycle)
 {
 	__be32 *buffer;
@@ -552,6 +630,80 @@ static void handle_out_packet(struct amdtp_stream *s, unsigned int cycle)
 		update_pcm_pointers(s, pcm, data_blocks);
 }
 
+static void handle_in_packet(struct amdtp_stream *s,
+			     unsigned int payload_quadlets,
+			     __be32 *buffer)
+{
+	u32 cip_header[2];
+	unsigned int data_blocks, data_block_quadlets, data_block_counter;
+	struct snd_pcm_substream *pcm = NULL;
+
+	cip_header[0] = be32_to_cpu(buffer[0]);
+	cip_header[1] = be32_to_cpu(buffer[1]);
+
+	/*
+	 * This module supports 'Two-quadlet CIP header with SYT field'.
+	 * For convinience, also check FMT field is AM824 or not.
+	 */
+	if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
+	    ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH) ||
+	    ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) {
+		dev_info_ratelimited(&s->unit->device,
+				"Invalid CIP header for AMDTP: %08X:%08X\n",
+				cip_header[0], cip_header[1]);
+		goto end;
+	}
+
+	/* Calculate data blocks */
+	if (payload_quadlets < 3 ||
+	    ((cip_header[1] & CIP_FDF_MASK) ==
+				(AMDTP_FDF_NO_DATA << CIP_FDF_SFC_SHIFT))) {
+		data_blocks = 0;
+	} else {
+		data_block_quadlets =
+			(cip_header[0] & AMDTP_DBS_MASK) >> AMDTP_DBS_SHIFT;
+		/* avoid division by zero */
+		if (data_block_quadlets == 0) {
+			dev_info_ratelimited(&s->unit->device,
+				"Detect invalid value in dbs field: %08X\n",
+				cip_header[0]);
+			goto err;
+		}
+
+		data_blocks = (payload_quadlets - 2) / data_block_quadlets;
+	}
+
+	/* Check data block counter continuity */
+	data_block_counter = cip_header[0] & AMDTP_DBC_MASK;
+	if (data_block_counter != s->data_block_counter) {
+		dev_info(&s->unit->device,
+			 "Detect discontinuity of CIP: %02X %02X\n",
+			 s->data_block_counter, data_block_counter);
+		goto err;
+	}
+
+	if (data_blocks > 0) {
+		buffer += 2;
+
+		pcm = ACCESS_ONCE(s->pcm);
+		if (pcm)
+			s->transfer_samples(s, pcm, buffer, data_blocks);
+	}
+
+	s->data_block_counter = (data_block_counter + data_blocks) & 0xff;
+end:
+	if (queue_in_packet(s) < 0)
+		goto err;
+
+	if (pcm)
+		update_pcm_pointers(s, pcm, data_blocks);
+
+	return;
+err:
+	s->packet_index = -1;
+	amdtp_stream_pcm_abort(s);
+}
+
 static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
 				size_t header_length, void *header,
 				void *private_data)
@@ -571,6 +723,31 @@ static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
 	fw_iso_context_queue_flush(s->context);
 }
 
+static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
+			       size_t header_length, void *header,
+			       void *private_data)
+{
+	struct amdtp_stream *s = private_data;
+	unsigned int p, packets, payload_quadlets;
+	__be32 *buffer, *headers = header;
+
+	/* The number of packets in buffer */
+	packets = header_length / IN_PACKET_HEADER_SIZE;
+
+	for (p = 0; p < packets; p++) {
+		if (s->packet_index < 0)
+			return;
+		buffer = s->buffer.packets[s->packet_index].buffer;
+
+		/* The number of quadlets in this packet */
+		payload_quadlets =
+			(be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
+		handle_in_packet(s, payload_quadlets, buffer);
+	}
+
+	fw_iso_context_queue_flush(s->context);
+}
+
 /**
  * amdtp_stream_start - start transferring packets
  * @s: the AMDTP stream to start
@@ -595,7 +772,10 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 		[CIP_SFC_88200]  = {  0,   67 },
 		[CIP_SFC_176400] = {  0,   67 },
 	};
-	int err;
+	unsigned int header_size;
+	enum dma_data_direction dir;
+	fw_iso_callback_t cb;
+	int type, err;
 
 	mutex_lock(&s->mutex);
 
@@ -610,16 +790,26 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 	s->syt_offset_state = initial_state[s->sfc].syt_offset;
 	s->last_syt_offset = TICKS_PER_CYCLE;
 
+	/* initialize packet buffer */
+	if (s->direction == AMDTP_IN_STREAM) {
+		dir = DMA_FROM_DEVICE;
+		type = FW_ISO_CONTEXT_RECEIVE;
+		header_size = IN_PACKET_HEADER_SIZE;
+		cb = in_stream_callback;
+	} else {
+		dir = DMA_TO_DEVICE;
+		type = FW_ISO_CONTEXT_TRANSMIT;
+		header_size = OUT_PACKET_HEADER_SIZE;
+		cb = out_stream_callback;
+	}
 	err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
-				      amdtp_stream_get_max_payload(s),
-				      DMA_TO_DEVICE);
+				      amdtp_stream_get_max_payload(s), dir);
 	if (err < 0)
 		goto err_unlock;
 
 	s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
-					   FW_ISO_CONTEXT_TRANSMIT,
-					   channel, speed, 0,
-					   out_stream_callback, s);
+					   type, channel, speed, header_size,
+					   cb, s);
 	if (IS_ERR(s->context)) {
 		err = PTR_ERR(s->context);
 		if (err == -EBUSY)
@@ -632,12 +822,17 @@ int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 
 	s->packet_index = 0;
 	do {
+		if (s->direction == AMDTP_IN_STREAM)
+			err = queue_in_packet(s);
+		else
 			err = queue_out_packet(s, 0, true);
 		if (err < 0)
 			goto err_context;
 	} while (s->packet_index > 0);
 
-	err = fw_iso_context_start(s->context, -1, 0, 0);
+	/* NOTE: TAG1 matches CIP. This just affects in stream. */
+	err = fw_iso_context_start(s->context, -1, 0,
+				   FW_ISO_CONTEXT_MATCH_TAG1);
 	if (err < 0)
 		goto err_context;
 

sound/firewire/amdtp.h

@@ -41,6 +41,8 @@ enum cip_sfc {
 	CIP_SFC_COUNT
 };
 
+#define AMDTP_IN_PCM_FORMAT_BITS	SNDRV_PCM_FMTBIT_S32
+
 #define AMDTP_OUT_PCM_FORMAT_BITS	(SNDRV_PCM_FMTBIT_S16 | \
 					 SNDRV_PCM_FMTBIT_S32)